// JQuery URL Parser
// Written by Mark Perkins, mark@allmarkedup.com
// License: http://unlicense.org/ (i.e. do what you want with it!)

jQuery.url = function()
{
    var segments = {};
    
    var parsed = {};
    
    /**
    * Options object. Only the URI and strictMode values can be changed via the setters below.
    */
      var options = {
    
        url : window.location, // default URI is the page in which the script is running
        
        strictMode: false, // 'loose' parsing by default
    
        key: ["source","protocol","authority","userInfo","user","password","host","port","relative","path","directory","file","query","anchor"], // keys available to query 
        
        q: {
            name: "queryKey",
            parser: /(?:^|&)([^&=]*)=?([^&]*)/g
        },
        
        parser: {
            strict: /^(?:([^:\/?#]+):)?(?:\/\/((?:(([^:@]*):?([^:@]*))?@)?([^:\/?#]*)(?::(\d*))?))?((((?:[^?#\/]*\/)*)([^?#]*))(?:\?([^#]*))?(?:#(.*))?)/,  //less intuitive, more accurate to the specs
            loose:  /^(?:(?![^:@]+:[^:@\/]*@)([^:\/?#.]+):)?(?:\/\/)?((?:(([^:@]*):?([^:@]*))?@)?([^:\/?#]*)(?::(\d*))?)(((\/(?:[^?#](?![^?#\/]*\.[^?#\/.]+(?:[?#]|$)))*\/?)?([^?#\/]*))(?:\?([^#]*))?(?:#(.*))?)/ // more intuitive, fails on relative paths and deviates from specs
        }
        
    };
    
    /**
     * Deals with the parsing of the URI according to the regex above.
      * Written by Steven Levithan - see credits at top.
     */        
    var parseUri = function()
    {
        str = decodeURI( options.url );
        
        var m = options.parser[ options.strictMode ? "strict" : "loose" ].exec( str );
        var uri = {};
        var i = 14;

        while ( i-- ) {
            uri[ options.key[i] ] = m[i] || "";
        }

        uri[ options.q.name ] = {};
        uri[ options.key[12] ].replace( options.q.parser, function ( $0, $1, $2 ) {
            if ($1) {
                uri[options.q.name][$1] = $2;
            }
        });

        return uri;
    };

    /**
     * Returns the value of the passed in key from the parsed URI.
       * 
     * @param string key The key whose value is required
     */        
    var key = function( key )
    {
        if ( jQuery.isEmptyObject(parsed) )
        {
            setUp(); // if the URI has not been parsed yet then do this first...    
        } 
        if ( key == "base" )
        {
            if ( parsed.port !== null && parsed.port !== "" )
            {
                return parsed.protocol+"://"+parsed.host+":"+parsed.port+"/";    
            }
            else
            {
                return parsed.protocol+"://"+parsed.host+"/";
            }
        }
    
        return ( parsed[key] === "" ) ? null : parsed[key];
    };
    
    /**
     * Returns the value of the required query string parameter.
       * 
     * @param string item The parameter whose value is required
     */        
    var param = function( item )
    {
        if ( jQuery.isEmptyObject(parsed) )
        {
            setUp(); // if the URI has not been parsed yet then do this first...    
        }
        return ( parsed.queryKey[item] === null ) ? null : parsed.queryKey[item];
    };

    /**
     * 'Constructor' (not really!) function.
     *  Called whenever the URI changes to kick off re-parsing of the URI and splitting it up into segments. 
     */    
    var setUp = function()
    {
        parsed = parseUri();
        
        getSegments();    
    };
    
    /**
     * Splits up the body of the URI into segments (i.e. sections delimited by '/')
     */
    var getSegments = function()
    {
        var p = parsed.path;
        segments = []; // clear out segments array
        segments = parsed.path.length == 1 ? {} : ( p.charAt( p.length - 1 ) == "/" ? p.substring( 1, p.length - 1 ) : path = p.substring( 1 ) ).split("/");
    };
    
    return {
        
        /**
         * Sets the parsing mode - either strict or loose. Set to loose by default.
         *
         * @param string mode The mode to set the parser to. Anything apart from a value of 'strict' will set it to loose!
         */
        setMode : function( mode )
        {
            options.strictMode = mode == "strict" ? true : false;
            return this;
        },
        
        /**
         * Sets URI to parse if you don't want to to parse the current page's URI.
         * Calling the function with no value for newUri resets it to the current page's URI.
         *
         * @param string newUri The URI to parse.
         */        
        setUrl : function( newUri )
        {
            options.url = newUri === undefined ? window.location : newUri;
            setUp();
            return this;
        },        
        
        /**
         * Returns the value of the specified URI segment. Segments are numbered from 1 to the number of segments.
         * For example the URI http://test.com/about/company/ segment(1) would return 'about'.
         *
         * If no integer is passed into the function it returns the number of segments in the URI.
         *
         * @param int pos The position of the segment to return. Can be empty.
         */    
        segment : function( pos )
        {
            if ( jQuery.isEmptyObject(parsed) )
            {
                setUp(); // if the URI has not been parsed yet then do this first...    
            } 
            if ( pos === undefined )
            {
                return segments.length;
            }
            return ( segments[pos] === "" || segments[pos] === undefined ) ? null : segments[pos];
        },
        
        attr : key, // provides public access to private 'key' function - see above
        
        param : param // provides public access to private 'param' function - see above
        
    };
    
}();